package prolog.builtins
import prolog.terms._

final case class dif() extends FunBuiltin("dif", 3) {
  override def exec(p: Prog) = {
    val x: Num = getArg(0).asInstanceOf[Num]
    val y: Num = getArg(1).asInstanceOf[Num]
    val r: Real = Real(x.getValue - y.getValue)
    putArg(2, r, p)
  }
}